diff --git a/plutus-benchmark/nofib/src/PlutusBenchmark/NoFib/Queens.hs b/plutus-benchmark/nofib/src/PlutusBenchmark/NoFib/Queens.hs
index 231f1a0d00c..097f47c76cb 100644
--- a/plutus-benchmark/nofib/src/PlutusBenchmark/NoFib/Queens.hs
+++ b/plutus-benchmark/nofib/src/PlutusBenchmark/NoFib/Queens.hs
@@ -203,6 +203,7 @@ instance TxPrelude.Eq Assign
     where (a := b) == (a' := b') = a==a' && b==b'
 instance TxPrelude.Ord Assign
     where (a := b) < (a' := b') = (a<a') || (a==a' && b < b')
+          (a := b) <= (a' := b') = (a<a') || (a==a' && b <= b')
 
 type Relation = Assign -> Assign -> Bool